Connecting part for applicators

ABSTRACT

The invention relates to a connecting arrangement for applicators, particularly for applicators which are used for applying liquid or pasty media, comprising a connecting part ( 1 ) and a sleeve-shaped holding portion ( 4 ), said connecting part ( 1 ) being equipped with a head and a stem ( 3 ) which is arranged on said head ( 2 ), said stem being formed along a stem axis ( 7 ) and having a free end, and said holding portion ( 4 ) being intended to receive said stem, said stem ( 3 ) and said holding portion ( 4 ) comprising at least one locking element ( 10, 11 ), respectively, which locking elements cooperate for the purpose of obtaining a connection when said stem ( 3 ) is inserted into said holding portion ( 4 ) in order to make it difficult to pull out said stem ( 3 ) from said holding portion ( 4 ).

The present invention relates to a connecting arrangement forapplicators, particularly for applicators which are used for applyingliquid or pasty media, and to a special connecting part.

From the prior art, applicators are known which comprise a head and astem. While the head (which may advantageously be flocked) is used forthe actual application of the media, the stem arranged on the headserves to hold the head or to fix it to a carrier. In the prior art, acarrier of this kind, which may be arranged inside the screw cap of aphial for cosmetics, for example, comprises a sleeve-shaped end sectioninto which the stem of the connecting part with the head arranged on itmay be inserted and, as the case may be, fixed.

Various kinds of connecting parts are known from the prior art, in whichthe different profile of the respective stem for attachment in theassociated holding portion is to be taken into account individually.This results in the disadvantage that different requirements are to betaken into account in order to fix the different stems in the sleeves ofthe holding portions, which leads to increased technical complexity inview of a large diversity of connecting parts or heads.

It is therefore the object of the invention to provide a simple andsufficiently strong connection between the connecting part and thesleeve. Another object is to provide a connecting part for applicatorswhich makes the connection with the associated holding portionsparticularly easy.

This object is achieved with an arrangement according to claim 1 and aconnecting part according to claim 7.

The invention is based on the idea that particularly simple and securefixing of the stem in the holding portion is guaranteed by the fact thatthe stem and the holding portion comprise at least one locking element,respectively, which locking elements cooperate when the stem is insertedinto the holding portion to obtain a connection therebetween in such away that pulling out the stem from the holding portion is made moredifficult. The respective locking elements may engage one behind theother or may cooperate in any other positive-locking way so that arelative movement between the holding portion and the stem is made moredifficult or even prevented entirely.

According to the invention, the locking elements cooperating with eachother may have different shapes. For example, a projection inside themostly tubular holding portion, which is approximately pin-shaped, mayengage a corresponding groove or recess in the stem. In this case, thelocking element or elements of the stem has/have a different shape thanthat of the locking element or elements of the holding portion.Inversely, the locking elements cooperating, respectively, may haveprincipally the same shape, so a substantially triangular projection onthe stem may cooperate with a triangular projection of the same kindinside the holding portion, for example. Advantageously, the possiblecooperation of differently shaped locking elements on the stem or theholding portion allows to use a particularly large diversity of lockingelements, and optimum, fast and cost-efficient manufacture thereof mayserve as a criterion of choice here.

The locking elements on the stem and/or in the holding portion may beconfigured to fully extend along the periphery in the circumferentialdirection. Alternatively, individual locking elements may also bedistributed over the periphery, which is preferably done at equaldistances in the circumferential direction. For example, fourprojections which are displaced by 90 degrees, respectively, and whichonly have a small width, respectively, may be formed on the stem. Thismakes it possible to push the stem (perhaps with partial plasticdeformation of the projections) through beneath a locking element insidethe holding portion. This associated locking element inside the holdingportion may be bead extending towards the inner side and over the entireperiphery, for example, behind which the four locking elements of thestem engage when the stem has been inserted. What is also conceivable,however, is to use four recesses on the inner side of the holdingportion which are distributed in the same way and in which one of thelocking elements of the stem may engage, respectively. This will alsoguarantee a non-rotative connection between the stem and the holdingportion.

Several locking elements arranged one behind the other in thelongitudinal direction are conceivable both on the stem and on theholding portion, too. For example, a profile of several peripheralgrooves formed one behind the other in the stem in the axial directionmay cooperate with one or several knobs which project from the innerside of the holding portion. The knobs may engage in one of theperipheral grooves of the stem when the stem is pushed into the holdingportion. Here, the depth of insertion may be chosen freely, anddepending on the depth of insertion the knobs formed in the holdingportion may engage in a different groove of the stem.

Principally, both the locking elements of the stem and those of theholding portion may extend entirely around the respective axis or may beuniformly or non-uniformly distributed over the periphery.

According to a particularly simple and effective embodiment of theconnecting arrangement according to the invention, elevations andimpressions are provided as locking elements on the stem and in thereceiving portion which have wedge-shaped, partially circular,knob-shaped, triangular, polygonal or irregular cross-sections.Depending on the shape, particularly effective engagement portions canbe achieved, which optionally make it easier, more difficult or notpossible at all to pull the stem and the holding portion apart.

According to another advantageous embodiment of the invention, a fixturebetween the stem and the receiving portion which is variable regardingthe depth of insertion and yet stable is achieved by providingperipherally extending impressions or elevations as convolutions,parallel, axially spaced grooves, or portions of the stem or thereceiving portion with a larger or smaller cross-section which extend inthe form of waves, as a locking element on the stem and/or a lockingelement in the receiving portion. Such peripherally extendingimpressions or elevations may cooperate with other locking elementswhich engage in the impressions. The locking elements cooperating witheach other, respectively, may be configured to be complementary to eachother so that, in the state in which they engage, the respectivecross-sections of the locking elements supplement each other to a largeextent or even completely to form a continuous surface. A stem, forexample, whose locking element is chosen to be a wave-shaped profile,and a correspondingly complementary, wave-shaped inner profile of thereceiving portion may be assigned to each other. This results inmultiple positive locking and thus in a particularly stable connection.In order to facilitate the action of inserting the stem, it is alsopossible to provide only one circumferentially extending groove or onlyone locking element which is not configured to extend circumferentiallyand which cooperates with a locking element that is configured to becomplementary thereto.

According to another advantageous embodiment of the invention, it isintended that at least one locking element comprises an insertion slopeso as to facilitate the action of inserting the stem and so that alocking element can engage behind it after the stem has been inserted.For this purpose, a profile with a triangular cross-section isparticularly suitable, with one side of the triangle rising from thesurface of the stem or the inner wall of the receiving portion in aninclination and then abruptly falling back again towards the originaldiameter. An insertion slope of this kind facilitates the insertion ofthe stem into the receiving portion (potentially with a slightdeformation of the stem or the receiving portion). As soon as the twocooperating locking elements are pushed past one another, they engageone behind the other, whereby it is made difficult to pull the stem andthe holding portion apart. Here, the process of engagement of oneelement behind the other may be supported by the material of the stem orthe holding portion jerking back elastically as soon as the lockingelements are locked in their position forming the engagement portion.

Furthermore, the invention deals with the specific configuration of aconnecting part which can be used for the arrangement described above orindependently of it. The invention is based on the idea that a simpleand standardized connection between the connecting part and the holdingportion can be achieved if the stem has the shape of a peg at leastalong a section of the stem, which peg comprises impressions at regulardistances in the radial direction along the axis of the stem althoughthe maximum outer diameter remains substantially constant.

With such a shape, the stem may be introduced into the sleeve of everyholding portion and may be fixed in such a way that the potentiallyvariable depth of the respective sleeve is of minor importance only.

The stem of the connecting part according to the invention can be fixedin the sleeve particularly in such a way that, once the stem has beenintroduced into the sleeve, it is achieved that the stem gets stuck inthe sleeve as a result of the sleeve being compressed from outside by aspecific amount in at least one predetermined place. In case of apermanent deformation of the sleeve in the area in which it iscompressed, at least a frictional connection is created between thesleeve and the stem.

It is particularly advantageous if the stem gets stuck in a place inwhich the stem inside the sleeve comprises one of the aforesaidimpressions. In this case, the material of the sleeve can be partiallypushed into the impression of the stem in such a way that, apart from africtional connection, a positive-locking connection, too, is createdbetween the stem and the sleeve, which results in a particularly firmconnection.

Alternatively, fixing can also be effected if the sleeve comprises, onits inner side, at least one projection, peg, nipple or the likeprojecting inside, which will rest in one of its aforesaid impressionswhen the stem is inserted. The projection then exerts a positive-lockingresistance against an axial relative movement of the stem and the sleeveso that the stem will be safely and sufficiently fixedly locked insidethe sleeve. Thus, the stem is pressed into the sleeve and is pushedalong or past the projection inside the sleeve with one or several ofits radial impressions. In this situation, the sleeve may be temporarilywidened and/or the at least one projection may give at least to such anextent that inserting and locking of the stem in the depth of the sleevechosen is possible without jeopardizing the desired stability andstrength of the connection.

As compared to the first variant of a connection mentioned, it ispossible here to refrain from allowing the sleeve and the stem to getstuck by exerting an external clamping force onto the sleeve, whichsaves time and money.

The at least one projection inside the sleeve may also be configured asa continuous or periodically discontinuous, ring-shaped bead on theinner wall of the sleeve. However, only a few projections or even only asingle projection, which may be dot-shaped, for example, may besufficient, as well. Furthermore, several projections may be spacedapart from one another along the inner wall of the sleeve in the axialdirection in such a way that their distance corresponds to the distanceof the regular impressions of the stem. This increases the strength ofthe connection since, in this case, several projections may engage indifferent impressions and together achieve an increased holding effect.

Advantageously, the regular distances of the impressions according tothe invention make it possible to variably fix the stems in the sleevesas far as the depth of insertion is concerned. Namely, theabove-mentioned stable fixture can be made by clamping the sleeve or byengagement using inner sleeve projections in the area of one or severalarbitrary impressions of the stem, which principally makes differentdepths of insertion of the stem in the sleeve of the holding portionpossible. Thus, according to the invention, the stem—which in thisrespect may be called standardized—makes it possible to fix differentheads in sleeves of different depths largely irrespective of therespective depth of the sleeve or the length of the head arranged on thestem, whereby a large number of different shapes of the stem known fromthe prior art can advantageously be avoided and manufacturing differentapplicators can be simplified to a large extent. The standardized shapeof the stem according to the invention makes it possible for differentheads and different depths of the sleeve to flexibly adjust to a desiredoverall length of the applicator into which the stem of the connectingpart in the sleeve can be inserted with substantially variable depth.

In an advantageous embodiment of the invention, the impressions areprovided as troughs of an imaginary wave which is directed in parallelto the axis of the stem and extends peripherally about the axis. Thus,the stem has the shape of a peg which, in the axial direction,periodically varies between a maximum and a minimum as far as its outerdiameter is concerned. The wave shape is particularly advantageous inthat the transition between an impression and a corresponding elevationis smoother or has a gradient that can be chosen. The sharp edges in thetransition area between the impression and the elevation which areavoided thereby advantageously make it possible to obtain a particularlyfirm connection between the stem and the surrounding sleeve since thesleeve compressed from the outside can be pressed into such awave-shaped impression more easily than in case of a sharp-edged groove,for example. Furthermore, it is easier to press the sleeve into a troughof a wave than to actually deform the sleeve, whereas pressing thesleeve into a sharp-edged groove rather has the character of adeep-drawing process in which the flow of material inside the sleeve isnecessary and the connection is thereby rather weakened. In case ofprojections arranged inside the sleeve, the wave shape also simplifiesthe process of engagement since there are no sharp edges on thetransitions.

Furthermore, with the wave shape, the existing material of the stem canbe utilized optimally, while sharp-edged transitions and thus zoneswhich are likely to break can advantageously be avoided.

The peg which comprises the radial impressions or the wave shape mayhave—perpendicularly to its longitudinal axis—a substantiallyrotationally symmetrical cross-section, which has the effect of aparticularly good inner stability of the stem. Principally, however, allbodies which are substantially longish are conceivable whosecross-sectional shape it not necessarily circular or rotationallysymmetrical. In particular, as cross-sectional shapes, rectangular,square, triangular or principally every polygonal shape are to bementioned here, which may also be irregular, i.e. with sides ofdifferent lengths. Also, a body having a cross-section in the form of astar (ridges extending outwardly from a center) constitutes a suitablecross-section, just like elliptical shapes. Not entirely symmetricalcross-sections are conceivable, as well, such as U-shaped or Z-shapedcross-sections. Furthermore, a polygonal cross-section does not have tobe filled and can be hollow inside. What is always decisive in thesubstantially free or arbitrary cross-sectional shape of the peg is thatit has the impressions according to the invention in its longitudinaldirection and that the stability connected with the material requiredand with the weight is chosen to be optimal.

In case of connecting parts which are not round in their cross-section(or in the area of the peg to be fixed), a wave shape—which is notabsolutely necessary—may be formed by combining the (for example,polygonal) shape of the peg with a peripherally extending wave.

According to the invention, an advantageous embodiment of the connectingpart is configured such that the wave profile is formed by at least twosuccessive impressions and elevations. With these two impressions, thevariable depth of insertion or fixture inside the sleeve of the holdingportion is already possible while, at the same time, only the minimumamount of material that is required for the stem is used. For thisreason, this embodiment constitutes a most simple variant of theinvention.

According to another advantageous embodiment of the invention, the freeend of the stem rests in an impression. The free end of the stem whichis remote from the head can be introduced into the sleeve of the holdingportion particularly easily if the outer diameter at this free end isreduced as compared to the inner diameter of the sleeve. This makes iteasier to introduce the stem into the sleeve, which is particularlyuseful if the axis of the sleeve is slightly displaced from the axis ofthe stem. If the final impression at the free end of the stem is atrough of a wave, the gradient towards the first wave crestsimultaneously acts as a centering means when the stem is furtherintroduced into the sleeve.

According to another advantageous embodiment of the invention, the axialdistance of the regular impressions along the stem is preferably one totwo millimeters. With this distance, the required number ofpossibilities of fixing or of clamping points on the sleeve can beachieved without the stem itself being configured to be too filigreed.

According to another advantageous embodiment of the invention, the ratioof the maximum outer diameter to the minimum outer diameter of the stemin the area of the stem section provided with the impressions is chosento be 3:2. This ratio turned out to be particularly suitable inpractice, so, with a core diameter in the area of the impression and its1.5-fold value of the maximum outer diameter, the stem is formed to besufficiently stable on the one hand and offers sufficient scope ofimpression to press in the sleeve. A maximum outer diameter of the stemto be chosen advantageously is currently 2.6 mm or 3.0 mm since thiscorresponds to the commonly used sleeve diameters. However, this doesnot exclude other sizes.

Advantageously, the stem is formed of plastics, although other materialsare principally conceivable, too. A certain flexibility of the materialis useful in so far as, during clamping, the sleeve compressed there canbe optimally adjusted to the stem if the stem is configured to bepliable or flexible at least to a small extent, too.

Below, an embodiment of the invention is explained in greater detailwith the aid of an example shown in the Figures.

FIG. 1 shows, in a schematic side view, a part of an applicator 1. Theapplicator comprises a head 2, which is arranged on a stem 3, and thehead and the stem form the connecting part according to the invention.The stem 3 extends from the head substantially along an axis 7 andprojects into a sleeve 4. The sleeve 4 is part of a holding portion andmay be integrally formed with a screw cap of a container, such as aphial for cosmetics, for example, which is not shown in FIG. 1.

As is apparent, the stem 3 has a wave-shaped profile which is formedrotationally symmetrically about the axis 7. Hereby, peripheralimpressions 5 and elevations 6 are created on the stem, which—seen inthe axial direction—blend smoothly.

Outside the sleeve 4, two plungers 8 are indicated, which can be pressedinto the sleeve 4 from outside in the radial direction so as to obtain aclamping connection in such a way that the material of the sleeve ispressed into one of the peripheral impressions 5 of the stem 3 in thearea of the point of compression.

As will be easily visible, the wave-shaped design of the stem allows torealize arbitrary depths of insertion into the sleeve 4; advantageously(but not necessarily), the point of clamping by the plungers 8 is to bechosen such that clamping is effected in the area of an impression 5 ofthe stem 3, respectively.

FIG. 2 shows a connecting part 1 with the wave-shaped stem 3 that hasalready been described. What is visible here are the impressions 5 andelevations 6 along a peg-shaped section of the stem 3. Here, however,the sleeve 4 is not intended to be used for clamping from outside.Rather, it comprises two peripheral projections in the form of beads (9)radially projecting inwardly on its inner side. When the stem has beeninserted, they engage in two impressions (5) of the stem (3) and thusavoid a relative movement between the stem and the sleeve, hereby makinga firm connection possible.

FIG. 3 shows, as an example, six different embodiments of the connectingpart 1, with the respective stem 3 showing different locking elements10. Only connecting element a) is provided with reference numerals, butthe reference numerals analogously apply to the other embodiments b) tof), too.

The stem 3 according to embodiment a) shows, in a sectional view, a waveprofile in which both a wave trough and a wave crest is to be understoodas a locking element 10, respectively. An associated locking element 11arranged inside a receiving portion (see FIG. 4) may then engage in awave trough 10 and may form a positive-locking fixture particularly withan adjacent wave crest 10.

The embodiment according to FIG. 3 b shows locking elements which arecreated by peripheral grooves on the stem 3. Although the bottom of thegrooves is chosen to be round here, it is principally possible to alsochoose any other suitable groove cross-section.

The embodiment according to c) shows locking elements which are createdby an outer thread on the stem 3. A thread of this kind may principallyalso be used to screw the stem into an associated holding portion.However, it is intended that pushing the stem in without any rotarymovement is possible according to the invention, too; again, associatedlocking elements of the receiving portion may engage in the individualimpressions of the thread.

The embodiment according to d) in FIG. 3 shows a slightly increasingwedge profile; this profile can be a peripherally extending, broadenedportion or wedge-shaped elements which are uniformly distributed overthe periphery. When the variant d) is inserted into the receivingportion (not shown), the receiving portion or the locking elementsarranged in the receiving portion are widened a little to then engagebehind the sharp-edged shoulder of the wedge-shaped locking elements ofthe stem 3.

The embodiment according to e) shows a bead-like, widened portionwhereas according to f) a substantially triangular cross-sectionalprofile is configured as a locking element. Other profiles areconceivable, too, in order to create a stable connection to be formedeasily between the stem and the holding portion.

In FIG. 4, sectional views of variants a) to j) of holding portions 4are shown, with reference numerals for the associated locking elements11 being included in variant f) only. In variant a), a wedge-shapednarrow portion is visible, which may cooperate with variant d) of FIG.3, for example, in such a way that a sharp-edged engagement portion iscreated. In principal, however, all the inner profiles of receivingportion 4 shown can be combined with outer profiles or locking elements10 of a stem 3 which are not configured to be identical or complementaryto each other. According to the invention, this results in aparticularly large and practical diversity of possible combinations.

1. A connecting arrangement for applicators, particularly forapplicators which are used for applying liquid or pasty media,comprising a connecting part (1) and a sleeve-shaped holding portion(4), a) said connecting part (1) being equipped with a head and a stem(3) which is arranged on said head (2), said stem being formed along astem axis (7) and having a free end, and b) said holding portion (4)being intended to receive said stem, characterized in that c) said stem(3) and said holding portion (4) comprise at least one locking element(10, 11), respectively, which locking elements cooperate for the purposeof obtaining a connection when said stem (3) is inserted into saidholding portion (4) in order to make it difficult to pull out said stem(3) from said holding portion (4).
 2. A connecting arrangement accordingto claim 1, characterized in that the inner side of said holding portion(4) and/or the outer side of said stem (3) comprises several lockingelements (10, 11) which are uniformly distributed over the peripheryand/or are arranged one behind the other in the longitudinal direction.3. A connecting arrangement according to one of the preceding claims,characterized in that elevations and impressions which havewedge-shaped, partially circular, knob-shaped, triangular, polygonal orirregular cross-sections are provided as a locking element (10) on thestem (3) and/or a locking element (11) in the receiving portion (4). 4.A connecting arrangement according to one of the preceding claims,characterized in that, as a locking element (10) on the stem (3) and/ora locking element (11) in the receiving portion (4), peripherallyextending impressions or elevations are provided as a) convolutions, b)parallel, axially spaced grooves or c) portions with a larger or smallercross-section which extend in the form of waves of the stem (3) or thereceiving portion (4).
 5. A connecting arrangement according to one ofthe preceding claims, characterized in that said at least one lockingelement (10) of said stem (3) is configured to be complementary to theat least one locking element (11) in the receiving portion (4) in such away that the respective cross-sections of the locking elementssupplement each other to a large extent or even completely.
 6. Aconnecting arrangement according to one of the preceding claims,characterized in that at least one locking element (10, 11) comprises aninsertion slope so as to facilitate the action of inserting the stem (3)and so that a locking element (10, 11) can engage behind it after thestem (3) has been inserted.
 7. A connecting part (1) for applicators,particularly according to one of the preceding claims, said connectingpart (1) being equipped with a head and a stem (3) which is arranged onsaid head (2), said stem being formed along a stem axis (7) and having afree end, and said stem (3) being intended to be received in asleeve-shaped holding portion (4), characterized in that said stem (3)has the shape of a peg at least along a section of the stem, which pegcomprises impressions (5) at regular distances in the radial directionalong the axis (7) of said stem.
 8. A connecting part according to thepreceding claim, characterized in that the cross-section of said peg hasthe shape of a) a regular or irregular polygon b) an ellipse c) a U or aZ or d) a star having at least two ridges which extend outwardly from acenter.
 9. A connecting part according to one of claims 7 to 8,characterized in that said impressions (5) are the troughs of animaginary wave directed in parallel to said axis (7) and extendingperipherally about said axis.
 10. A connecting part according to claim9, characterized in that said wave profile is formed by at least twosuccessive impressions (5) and elevations (6).
 11. A connecting partaccording to one of claims 7 to 10, characterized in that said free endof said stem (3) rests in an impression (5).
 12. A connecting partaccording to one of claims 7 to 11, characterized in that the axialdistance of the regular impressions is 1 mm.
 13. A connecting partaccording to one of claims 7 to 12, characterized in that the ratiobetween the maximum outer diameter and the minimum outer diameter ofsaid stem (3) in the area of said peg is chosen to be 3:2.
 14. Aconnecting part according to one of claims 7 to 13, characterized inthat it is made of plastics.
 15. A connecting part (1) and asleeve-shaped holding portion (4) for a connecting part according to oneof the preceding claims, characterized in that said holding portion (4)a) can be deformed permanently after the stem has been inserted byexerting radial external forces onto the holding portion in such a waythat the stem (3) present inside can be fixedly connected with saidholding portion (4), or b) that said holding portion comprises, on itsinner wall, at least one projection (9) extending radially inwardly oroutwardly, which cooperates with at least one radial impression orelevation (5) of said stem (3) inserted so as to prevent a relativemovement of the holding portion (4) and the stem (3).